import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;

public class MySQLAccess {

	private Connection connect = null;
	private Statement statement = null;
	private ResultSet resultSet = null;

	public void connectDB() {

		try {

			Class.forName("com.mysql.jdbc.Driver");

			connect = DriverManager
					.getConnection("jdbc:mysql://localhost/merx?"
							+ "user=root&password=admin");

			statement = connect.createStatement();

		} catch (Exception e) {

			System.out.println("Failed to connect to MySQL DB");
			e.printStackTrace();
		}


	}

	public void readDataBase() {

		try {

			connectDB();

			resultSet = statement
					.executeQuery("select * from merx.inventory;");

			writeResultSet(resultSet);

		} catch (Exception e) {

			e.printStackTrace();

		} finally {

			close();
		}
	}

	public void test() {

		try {

			connectDB();

			String[] values = { "TEST", "TEST", "TEST" };
			String query = String.format("INSERT INTO merx.category " +
										 "(code, description, name) " +
										 "values (\"%s\", \"%s\", \"%s\");",
										 values[0], values[1], values[2]);

			int res = statement.executeUpdate(query);
			resultSet = statement.executeQuery("SELECT LAST_INSERT_ID();");
			writeResultSet(resultSet);
			statement.executeUpdate("DELETE FROM merx.category WHERE code = \"TEST\";");

		} catch (Exception e) {

			e.printStackTrace();
		}

	}

	private void writeResultSet(ResultSet resultSet) throws SQLException {
		ResultSetMetaData resMeta = resultSet.getMetaData();
		int colCount = resMeta.getColumnCount();

		while (resultSet.next()) {
			for (int i = 1; i <= colCount - 1; i++) {
				System.out.print(resultSet.getObject(i).toString() + "|");
			}
			System.out.println(resultSet.getObject(colCount).toString());
		}
	}

	private void close() {

		try {
			if (resultSet != null) {
				resultSet.close();
			}

			if (statement != null) {
				statement.close();
			}

			if (connect != null) {
				connect.close();
			}
		} catch (Exception e) {

		}
	}

}